Satellite sensors that measure infrared radiation infer the amount of heat emitted from an object at the earth's surface. Objects with an average earth temperature (roughly -50 to 50 degrees Celsius, or -58 to 122 degrees Fahrenheit) emit most of their energy in the infrared region.

Infrared sensors can easily detect sea ice because its temperature is generally much colder than the surrounding ocean. A typical winter sea ice temperature is -20 to -40 degrees Celsius (-4 to -40 degrees Fahrenheit), while the surrounding ocean temperature is above freezing. Limitations in measuring infrared radiation from space include the following: